<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    a:link{
      color: cyan;}
    a:visited{
      color: violet;}
    a:hover{
      color: slateblue;
    }
    a:active{
      color: lawngreen;
    }
  </style>
</head>
<body>
<a href="http://www.baidu.com">百度</a>
<a href="http://www.youku.com">优酷</a>
<a href="http://www.qq.com">腾讯</a>
<a href="http://www.bilibili.com">B站</a>
</body>
</html>